The Essex Coast CLM Spring 2017
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Conservation around the UK… Saltmarsh in the heart of the Colne Estuary. Chris Gibson The Essex coast ’ ’ more desolate region can scarce be Overview The coastline of Essex is conceived, and yet it is not without beauty.’ Summarised and updated from Gibson 2003. long, intricate and starkly A It is perhaps surprising that Reverend Baring-Gould’s description of the Essex coast, from Habitats beautiful. As well as his 1880 novel Mehalah, is as appropriate today As evidenced by the near-continuous suite of sites being the winter home as when it was first written. Despite the immense of national and international importance (SSSI, for huge aggregations changes wrought by the 20th century – intensive SPA, SAC and Ramsar sites), extending even over of waterbirds, it provides agriculture, urban expansion and industrial some of the most heavily developed frontages, the important habitat for development – which have eroded the essential Essex coast is of exceptional wildlife value. many rare plants and wildness of our coastline, it is still of national and The major habitat groups can conveniently be international significance for wildlife. And it is here divided by the seawall, itself a linear grassland of specialised invertebrates. for all to enjoy: some 15 million people live within considerable value. Outside the seawall, in the There are also serious an hour’s drive of the Essex coast. active coastal process zone, management is largely management challenges Essex has one of the longest coastlines of left to the sea, as it reforms and reshapes habitats, as balance is sought any English county. As the brent goose flies, while inside, more traditional human interventions between the pressures Manningtree to Purfleet, on the borders of Suffolk are required. of climate change and and Greater London respectively, are only 80km The most extensive intertidal habitats are found apart, but following the twists and turns around in the sheltered estuaries, where the finest particles human intrusion, and the estuaries and islands, the coast is more than 500km of suspended material (silt) are deposited. Mudflats need to safeguard this long. The coastline is a mosaic of habitats, from are formed at lower tidal levels, and contain a important landscape, as open sea, through mudflats and saltmarshes to rich invertebrate fauna, thriving on twice-daily Chris Gibson describes. the seawalls and grazing marshes. Each is home inundation by detritus-rich waters; in turn, this to outstanding wildlife, forming one of the most productivity supports internationally significant important areas of relatively undeveloped coastline populations of wetland birds. Continued deposition Copyright © Britishin the southern North Sea, although Wildlife each is subject raises the surface higher in the tidal range, until the to human and other pressures which require point where more terrestrial, albeit salt-tolerant, management. vegetation can survive, forming saltmarshes. The 16 Conservation Land Management Spring 2017 Spring 2017 Conservation Land Management 17 Conservation around the UK… The Essex coast Conservation around the UK… The Essex coast saltmarshes became brackish grazing marsh. By adding gulls, offshore seabirds and Where these have survived later drainage and other uncounted birds and stretches of coast, conversion to arable, they provide a valuable the Essex coast is home to more than half-a- adjunct habitat for wintering waterbirds, breeding million waterbirds each winter. The Siberian- habitat for some wildfowl and waders, and feeding breeding dark-bellied brent goose epitomises the areas for raptors. Grazing marsh vegetation reflects international importance of the Essex coast: almost its brackish nature, often with extensive stands a half of the world population winters on English of strawberry clover, hairy buttercup and spiny coastlines, and half of those do so in Essex. restharrow. Ditches ramifying through the grazing Of course, wintering waterbirds are not the only marshes are especially brackish, supporting distinct birds of interest. Several species (e.g. redshank, communities of specialised plants and invertebrates lapwing and shelduck) also breed, primarily on land which thrive in those conditions. managed specifically for them; raptors and owls While much of the coastal hinterland is now hunt over the marshes, particularly in winter; and intensive agriculture or urban, in a few places saltmarshes are an essential winter food source for semi-natural habitats complete the coastal suite, seed-eating birds, including twite and corn bunting. including woodland and coastal grassland. The Each Essex coastal habitat is characterised large reservoir at Abberton is only 2km from the by plants that have adaptations to cope with Blackwater Estuary, their birds showing regular the various environmental stresses. The table Dark-bellied brent goose, icon of the Esssex coast. Chris Gibson interchange. Especially by the Thames, large below includes those with a conservation status tracts of formerly industrial brownfield land have of near threatened or greater, based on IUCN developed considerable wildlife value, especially (International Union for Conservation of Nature) for invertebrates, reflecting the warm microclimate criteria, plus a selection now evaluated as least of the Thames Estuary and proximity to sources concern but which previously were considered of colonisation from the Continent. Pride of place nationally scarce or rare, simply on the basis of the among these is Canvey Wick SSSI, designated number of 10km squares occupied (see box below). specifically for its brownfield invertebrates, the As might be expected, given the range of highest concentration of rare species at any site in specialised habitats and plants, the Essex coast is the country. also home to many rare and localised invertebrates. Underlying many of these habitats, there are Of the two eponymous county insects, the Essex several SSSIs notified for their geological interest. skipper is widespread and often abundant, Most dramatically, the cliffs at Walton-on-the-Naze especially on seawalls, as over much of south- give a window into two key geological periods: eastern England; sadly, however, for reasons not when London Clay was laid down some 50 million entirely clear the Essex emerald moth became years ago, and Red Crag, a three-million-year-old extinct nationally in the 1990s. Two extant Fisher's estuarine moth, restricted to Annual sea-purslane – rarest plant beach deposit, the stratigraphic variation of fossils macromoths of importance are the ground lackey, north Essex and north Kent. Chris Gibson of the Essex coast – at its only British site. Top Extensive Thames-side Essex coast is especially important for saltmarshes, therein providing the earliest accessible evidence of whose larvae live in conspicuous communal ‘nests’ Chris Gibson mudflats, of great wildlife value supporting around one tenth of the total UK the onset of the last ice age. on saltmarshes, and Fisher’s estuarine moth, despite the largely developed frontage. Chris Gibson resource. These range from low marsh dominated feeding on hog’s-fennel and consequently restricted Mudflats Dwarf eel-grass VU; Common eel-grass NT by annuals such as glasswort, through middle Species to the north Essex and north Kent coasts. Bottom The Naze cliffs, marsh, characterised by saltmarsh-grasses and sea- Each of the constituent estuaries is of international The seawalls support strong populations of Saltmarsh Annual sea-purslane CR; Small cord-grass EN; largely still allowed to erode as a Borrer’s saltmarsh-grass VU; Golden-samphire LC; necessary source of sediment for lavenders, to upper, shrubby marsh at the highest significance for one or more species of wintering Roesel’s bush-cricket, the heartland from which it the rest of the Essex coast. tidal levels. waterbird. Typical figures, summarised from the has colonised most of southern England over the Shrubby sea-blite LC; Perennial glasswort LC; Chris Gibson More localised deposits of coarser sand, shingle Wetland Bird Survey programme and rounded to past 20 years. Similarly, the grazing marsh ditches One-flowered glasswort LC; Marsh-mallow LC; Annual beard-grass LC; Lax-flowered sea-lavender LC; and shell provide additional, supratidal habitats. the nearest thousand, are shown in the table below. have served as a springboard for establishment of Curved hard-grass LC Necessarily tolerant of salt spray, drought and rare Odonata: scarce emerald and willow emerald Shell, shingle and sand Prickly saltwort VU; Bur medick VU; Sea-heath NT; mechanical disturbance from wave action, typical damselflies are now well-established, and the National Site Average total waterbirds Sea pea LC; Dune fescue LC; Bulbous meadow-grass LC; plants include sea-holly and marram grass on sand, rank (winter 2010–11 to 2014–15)* southern migrant hawker seems to be following Suffocated clover LC; Ray’s knotgrass LC; and yellow horned-poppy and sea kale on shell and 4 Thames** 170,000 suit. Tendring rock sea-lavender W; Rush-leaved fescue W; shingle. 16 Blackwater 75,000 Bermuda grass W Beyond the mudflats, the shallow sea is highly Conservation management 19 Hamford Water 52,000 Seawalls Least lettuce EN; Slender tare VU; Sea barley VU; turbid but supports shellfish, including native ‘Traditional’ conservation land management Slender hare’s-ear VU; Hog’s-fennel LC; Sea clover LC; 20 Dengie 52,000 oysters, now largely outcompeted by non-native is largely restricted to the habitats inside the